<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>除以0是无穷大无穷大是一个数字</title>
</head>
<body>
    
    <p id="demo"></p>
    <script>
        var y = 1000 / 0;
        document.getElementById("demo").innerHTML = isNaN(y);
    </script>

</body>
</html>